Dinitropyrroles



United States Patent 3,151,121 DINKTRGPYRRGLES George Karmas, Bound Brook, NJ assignor to Ortho Pharmaceutical Corporation, a corporation of New Jersey N0 Drawing. Filed Aug. 10, 1962, Ser. No. 216,034 13 Claims. (Cl. 260-2945) The present invention relates to l-substituted, 2,4-di nitropyrroles. Specifically, the new compounds may be represented by the following structural formula O NT L JNOs l OH O ON in which R is a substituent selected from the group consisting of hydrogen and alkyl radicals having no more than 4 carbon atoms. R is a substituent selected from the group consisting of hydrogen and alltyl radicals haiing no more than 4 carbon atoms, and R and R taken together may form a group consisting of piperidine and pyrrolidine.

The compounds of the present invention have antimicrobial activity and more specifically are effective against Trichomonas feoius, a parasitic protozoan that infects the uterus of animals and causes aboltion in cattle. The high order of trichornonodicidal activity possessed. by the compounds of the present invention is quite surprising.

It is an object of the present invention to provide new compounds having therapeutic utility in the treatment of animals infected With T riclzomonrzs foetus.

The following examples will serve to illustrate more full the method of preparing the novel compounds of the present invention.

EXAMlLE I l-Curbet/10xymethyl2,4-Dini1r0pyrrole A mixture of 5 grams (0.0275 mole) of the sodium salt of 2,4-dinitropyrrole, 6 milliliters of ethyl chloroacetate and l0 milliliters of dimethylformarnide is heated under reiiux for two hours. The reaction mixture is cooled and poured With stirring into a mixture of 200 milliliters of water, 100 grams ice, and 15 grains of sodium carbonate layered with 150 milliliters of e her. This mixture is shaken vigorously and then the layers are separated. The ether solution is Washed with 100 milliliters of 5% aqueous sodium carbonate, dried With anhydrou magnesium sulfate, concentrated, and then distilled. The 1-carhethoxyrnethyl-2,4-dinitropyrrole distills at Mil-145 C. at 0.003 mm, and melts at 8384 C,

EXAMPLE I 1 -Carboxymethyl-2,45initropyi'role To a cold (5 C.) solution of 5.2 grams (0.0214 mole) of l-carhethoxymethyl-2,4--dinitrcpyrrole (prepared according to the process of Ertaaple l) in 150 milliliters of methanol is added 0.855 gram (0.0214 mole) of so ium hydroxide in 10 milliliters of Water. To the resulting paste is added 200 milliters of Water and mixture is warmed at 45 C. for 10 minutes. After it has been cooled to 0 (3., this solutioiiis acidified with hydrochloric acid ice C, 33.50; H, 2.34. Found:

EXAMPLE III 1' (N,N-Diethyi) Acetamid0-2,4-Diizizropyrrole A mixture of 4.3 grams (0.0198 mole) of l-carboxymethyl-2,4-dinitropyrrole hydrate (prepared as described in Example II) and 30 milliliters of thionyl chloride is boiled under reflux for 2 /2 hours and then concentrated under vacuum at 60 C. The dark oily residue is dissolved in 20 milliliters of toluene and reconcentrated under vacuum at 60 C. The residue is then leached with 100 milliliters of dry ether and the ether solution is decanted from a little tarry matter into a vigorously stirred solution of 3 milliliters of diethylamine in milliliters of dry ether. After 2 hours of stirring at 25 C., 50 milliliters of Water, 5 grams of sodium bicarbonate, and milliliters of chloroform are added. The mixture is shaken vigorously and the layers are separated. After rying with magnesium sulfate, the ether solution is concentrated under vacuum. The residual dark solid is boiled briefly in 900 milliliters of Water and the mixture is filtered while hot, after addition of 5 grams of Supercel. Supercel is a diatomaceous silica filter aid manufactured by lohns-l /lanville. Slow chi ling of the filtrate to 0 C., allords l-(hLN-diethyl) acctammo-2,4-dinitropyrrole as small bull flakes of melting point 102-103 C. The yield is 2.4 grams (51.9%).

Calcd. for C H O N N, 20.73. Found: N, 20.82.

This compounds is prepared as described in Example Ill, using dry N-hutylamine in place of diethylamine. m Q o I: 2' the melting point is 13-134 (1, enter recrystallization from ethyl acetate, and the yield from an equal quantity of starting material is 2.3 grams (49.7%

Calcd. for C H OQQ: N, 20.73. Found: N, 20.32.

EXAMPLE V I (N-PrapylcarbamylmelhyI) -2,4-D initropyrrole A mixture of 5 grams ofthe sodium salt of 2,4- dinitropyrrole, 4.2 grams of N-propylchloracetamide, and 0 milliliters of dimethylformamide is boiled under reflux for 1" teen minutes and then poured into 300 milliliters of cold 5% aqueous potassium carbonate. The insoluble solid is filtered ol'r', ried in air and decolorized with charcoal in an acetone solution. The clear filtrate is evaporated to dryness and the solid residue is recrystallized from ethyl acetate to afford 4.8 grams (68%) of l-(N-propylcarhamylmethyl)-2,4-dinitropyrrole as fine cream prisms Which melt at 126-127".

The experimental details and physical constants of other compounds of thepresent invention prepared according to the methods illustrated in Example I through V above, appear in Tables I and H. The constants of compounds not listed in Table II may be found in the detailed Example I through V.

Preparation From Chloroacetamides Reaction Condi- Yield, R Alkylating Agent tlons (in Dipercent methyltormamldc) CHzCONHz lCH2CONEz.. min. at 145-. 59 CH2CONHOH3- ClCHgCONHCHa min. at150 67 CH2CON(CH3)Z-- 0lCHgCON(CH 15min. at l 78 CHz0ONHCzH5 ClCHqCONHCzH 15 min. at150 78 CHzC ONHCaH-I 010E1 0 ONHC H 15 min. at 150 68 0Hz0ONH03H7 CICHQCONHCQH, 15 min. at 150"... 67 0HgOONH04H9 ClCHlCONHCAHQl 5 min. at 150"... .8 CH2OON(OAH9) Cl0H2CON(C4Hu)z 5 min. at 150 74 OHQCON ClCHzC ON 15 min. at150 CHzCHz CHzCHg CHZCON /0Hz ClGHzCON CH2 15min. at 150 77 01120111 CHQCHR TABLE II Physical Constants of Carbamy[methyl-2,4-Dinitr0- pyrroles of Table I O N t L JNO:

Analytical R 13.1 M.I., deg.

Cjmm.

Calcd. Found CHzC ONE: 231-232 33.650, 38.810; 2.8711. 011 0 ONHOH3 167-168 36.850; 37.090; 3.7211. 01320 ON(CH )2. 141 39.670; 39.700; 4.2013. 01320 O NH0zH 161-162 39.670; 39.370; 4.3411. CH2CONHC3H7. 126-127 42.190; 42.280, 4.64H. GHQCONHCIiHT-i 176-177 42.190; 42.380; 4.6313. 011 0 ONHCrHqri 133434 44.440; 44.760; 5.41H. C11 0 ON(04H0)z 127-123 51.520; 51.420; 6.6911.

0Hz0 ON 158-159 44.780, 4.51H 1- 44.750; 4 5411 CHZOHQ CHzC ON 0H2 152-153 46.810; 5.0011 47.310; 5.17:5.

CHzOHg The in vitro trichomonadicidal activity of the compounds of the present invention may be demonstrated by a series of tests which establishes the minimal inhibitory concentration of these compounds. Minimal inhibitory concentration, as used above, is defined as the minimal concentration of a trichomonadicidal compound capable of preventing the growth of and killing Trichomonas foetus organisms introduced into a culture medium, capable alone of supporting a vigorous growth of the organisms and containing the trichomonadicidal compound to be tested. The culture medium used in thetests is described in a publication of Kupferberg, Johnson and Sprince, Proceedings of the Society for Experimental Biology and Medicine, volume 67, pages 304-308, 1948.

In making the tests to determine minimal inhibitory concentrations, 0.05 milliliter of a 48-hour culture of Trichomonas foetus is placed in a series of tubes containing 10 milliliters of the culture medium and increasing amounts of the compounds to be tested. The inocu- V lated culture medium is then incubated at 37 C. for nine days and examined under magnification after two, five,

' seven, and nine days. The minimal inhibitory concentration of the compound tested is that concentration in the tube in which no viable organisms are present at the ninth day examination. It thereare no viable organisms present on examination at a time less than nine days, the concentration of compound is greater than minimal and if there are Viable organisms present at the ninth day examination, the concentration is less than minimal. The results of these tests appear in column 1 of Table III, wherein the concentration of the carbamylmethyl-2,4- dinitropyrroles is expressed in parts per million.

The toxicity of the compounds of the present invention are determined by oral administration to mice and may be determined from the in vivo data appearing in Table III. In column 2, under the heading LDsu, is indicated the quantity (in milligrams per kilogram of body weight) which is fatal to 50% of the mice tested. The

the vaginal mucosa under the conditions of use. The ve- 45 hicle is preferably of a liquid or semi-liquid type. Furthermore, since the final preparation should be readily miscible with vaginal fluids, the vehicles, whether hydrous or anhydrous, are preferably water miscible or Water-dispersible. The compositions of this invention may be in the form of suppositories, if desired.

The foregoing criteria for a Vehicle in which the compounds of the present invention are incorporated may be met by a large number of semi-liquid chemotherapeutic vehicles that are Well known in the art. Thus, for example, the vehicle may comprise semi-liquids that are colloidal in nature, especially those that are viscous and/or mucilaginous in character. Such vehicles are particularly suitable for use in topical treatment of Trichomonas foetus becaus of their inherent gelatinous and miscible nature which aifords prolonged contact between the l-substituted-2,4-dinitropyrrole and the infecting organism.

In order to disclose more clearly the manner of formulating the compounds of the present invention to topical application, several specific examples will hereinafter be described in considerable detail.

EXAMPLE VI Deionized water 75.80 Sodium carboxymethylcellulose 3.00 70 Polyethyleneglycol (molecular weight approximate- Propylene glycol 5.00 Para-hydroxy-benzoic acid methyl ester 0.20 1-(N-propylcarbamylmethyl)-2,4-dinitropyrrole 1.00 75 5 6 amount (in milligrams per kilogram of body weight) re- EXAMPLE VII quired to cure 50% of the test animals injected with a Deionized water 90.30 lethal dose of Trichomonas foetus is indicated in column Methyl cellulose 3.50 3, under the heading PD In this column, NP. indi- Glycerin 5.00 cates no protection. Column 4 of Table III reports the 5 Para-hydroxy-benzoic acid methyl ester 0.20 therapeutic lndex of these compounds. l-(N-isobutylcarbamylmethyl)-2,4-dinitr0pyrrole 1.00

TABLE III Trichomonadicidal Activity of Carbamylmethyl-2,4- Dinitropyrroles N O i 2 R In Vitro In Vivo R Activity,

p.p.n1.

ao PD50 T.I

CHzCHz CHzCHz 0112C ON /OH3 1.0 2,150 07 52 In employing the trichomonadicides of the present in- EXAMPLE VIII vention for the treatment of Trichomonas foetus, one or 40 Deionized Water 80.80 more of the active agents are uniformly distributed in a Pectin 8.00 suitable chemotherapeutic vehicle that is chemically cOrn- Propylene glycol 10.0 patible with the particular trichomonadicide selected, non- Para-hydroxy-benzoic acid methyl ester 0.10 inhibiting with respect to the action of the effective agent Para-hydroxy-benzoic acid propyl ester 0.10 upon Trichomonas foetus and essentially non-injurious t0 1-(N-methylcarbamylmethyl)-2,4-dinitropyrrole 1.00

The trichomonodicidal formulations of Examples VI through VIII are prepared according to the following general procedure in which two initial solutions are mixed to make the formulation, all the parts being given by Weight. To prepare Solution A, dissolve the para-hydroxy-benzoic acid methyl ester in about two-thirds of the hot deionized water, cool to about 5., and, while stirring, add the gel-forming ingredient and glycerine r propylene glycol. To prepare Solution B, add the trichomonadicidal agent to the remainder of the deionized Water, and adjust the pH to the desired value. The formulation is prepared by adding Solution B to Solution A in a slow stream with good stirring; stirring is continued for at least one hour.

Certain compounds of the present invention have also been found to be effective against enterohepatitis (blackhead) when administered by admixture, suspension, or dispersion in the food and/ or drink normally partaken by turkeys, such as grain, mash, scratch, water or other liq: uids.

The general range of concentration of the l-substituted- 2,4-dinitropyrrole in the total substance is from about 0.05% or less to about 1%. The optimal concentration for effective therapy is in the range from about 0.05% to about 0.2% of the total food or drinking Water. With these optimal concentrations, the daily drug intake for infected birds varies from about 20 milligrams of drug per kilogram of body Weight to about 400 milligrams of drug per kilogram of body weight. In general, the precise dosage depends on the particular compound and the severity of the infection. Many of the compounds of the present invention may be administered in the concentrations indicated above with little or no toxic effects.

Various changes and modifications of the invention may be made and to the extent that such variations incorporate the spirit of thisinvention, they are intended to be included within the scope of the appended claims.

This application is a continuation-in-part of my copending applications Serial No. 23,383, filed April 20, 1960, now abandoned, Serial No. 124,767, filed July 18, 1961, and Serial No. 210,199, filed July 16, 1962.

What is claimed:

1. A compound of the formula C NT L JNOZ I omooNm 3. A compound of the formula OzNT L JNO: N

4. A compound of the formula O NT L JNOa 5. A compound of the formula OzN 6. A compound of the formula NO-z 7. A compound of the formula OZNT | C11 0 ONHGH;

8. A compound of the formula OZNT (IJHQG ON(OII3)2 9. A compound of the formula $1120 ONHCZH5 10. A compound of the formula L JNOa (IJHZCONKMHQM 12. A compound of the formula JH CON--(i7C H 13. A compound of the formula I CHzOON CHgCH N 0 references cited,

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No: 3,151, 121 September 29, 1964 George Karmas It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 35, for "C H O N read G H O N line 40, for "compounds" read compound column 8 lines 53 to 59, the formula should appear as shown below instead of as in the patent:

CH CON CH CH Signed and sealed this 2nd day of February 1965.

(SEAL) Attest:

EDWARD J. BRENNER ERNEST Wu SWIDER Commissioner of Patents Attesting Officer 

1. A COMPOUND OF THE FORMULA
 13. A COMPOUND OF THE FORMULA 